How Can Diffusion Be Observed?

Introduction: In this lab you will
observe the diffusion of a substance across a semi permeable membrane. Iodine
is a known indicator for starch. An indicator is a substance that changes
color in the presence of the substance it indicates. Watch as your teacher
demonstrates how iodine changes in the presence of starch.

Prelab Observations: Describe what
happened when iodine came into contact with starch.

Procedure:

Fill a plastic
baggie with a teaspoon of corn starch and a half a cup of water tie bag.
(This may already have been done for you)

Fill a beaker
halfway with water and add ten drops of iodine.

Place the baggie
in the cup so that the cornstarch mixture is submerged in the iodine water
mixture.